Lighting device

ABSTRACT

A lighting device may be provided that includes a light emitter including a plurality of LEDs; a reflective plate disposed on the light emitter; a diffuser plate disposed in a direction in which light emitted from the LED is irradiated; a case including the light emitter disposed therein and including a bottom plate and a side wall extending from both side ends of the bottom plate; and a connecting member extending from the side wall of the case and including a bracket coupler on at least one side thereof. The light emitter is disposed between the bottom plate of the case and the diffuser plate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 from KoreanApplication No. 10-2010-0112975, filed Nov. 12, 2010, No.10-2010-0112976, filed Nov. 12, 2010 and No. 10-2010-0112977, filed Nov.12, 2010, the subject matters of which are incorporated herein byreference.

BACKGROUND

1. Field

Embodiments may relate to a lighting device, and more particularly to anLED lighting device including a plurality of LEDs arranged therein.

2. Background

A light emitting diode (LED) is a semiconductor element for convertingelectric energy into light. An electric bulb has a short life span. Alonger time for use of the electric bulb allows the life span to beshorter. For this reason, the electric bulb is required to check andchange cyclically. Therefore, there has been a problem of paying for theadditional cost of changing and managing the electric bulb. As comparedwith existing light sources such as a fluorescent lamp and anincandescent electric lamp and so on, the LED has advantages of lowpower consumption, a semi-permanent span of life, a rapid responsespeed, safety and an environment-friendliness. Therefore, the LED isused as a light source for lighting devices, for example, various lampsused interiorly and exteriorly, a liquid crystal display device, anelectric sign and a street lamp and the like, as a result, is nowincreasingly taking the place of the electric bulb.

SUMMARY

One embodiment is a lighting device. The lighting device may include: alight emitter including a plurality of LEDs; a reflective plate disposedon the light emitter; a diffuser plate disposed in a direction in whichlight emitted from the LED is irradiated; a case including the lightemitter disposed therein and including a bottom plate and a side wallextending from both side ends of the bottom plate; and a connectingmember extending from the side wall of the case and including a bracketcoupler on at least one side thereof. The light emitter may be disposedbetween the bottom plate of the case and the diffuser plate.

Another embodiment is a lighting device. The lighting device mayinclude: a light emitter including a plurality of LEDs; a reflectiveplate being disposed on the light emitter and including a bottomreflective plate and a side reflective plate which extends from thebottom reflective plate and includes an inclination; a diffuser platedisposed in a direction in which light emitted from the LED isirradiated; a case including the light emitter disposed therein andincluding a bottom plate and a side wall extending from both side endsof the bottom plate; and a connecting member extending from the sidewall of the case and including a bracket coupler on at least one sidethereof.

Further another embodiment is a lighting device. The lighting device mayinclude: a light emitter including a plurality of LEDs; a reflectiveplate disposed on the light emitter; a diffuser plate being disposed ina direction in which light emitted from the LED is irradiated andincluding a locking part; a case including the light emitter disposedtherein and including a bottom plate and a side wall extending from bothside ends of the bottom plate; and a connecting member extending fromthe side wall of the case and including a bracket coupler on at leastone side thereof. At least one of the reflective plate or the case mayinclude a fastener fastened to the locking part of the diffuser plate.

The lighting device according to the embodiment may further include aheat radiator contacting with the light emitter.

The heat radiator may include at least one of a heat radiating fin or aheat radiating sheet.

The light emitter may be disposed closer to the diffuser plate than thebottom plate of the case.

The connection member may include a louver or a top plate. The bracketcoupler may be disposed at the end of the louver or the top plate.

The louver or the top plate may be inclined more outward than the sidewall.

The side wall of the case may include a first side wall and a secondside wall opposite to the first side wall. The connection member mayinclude a first connector extending from the first side wall and asecond connector extending from the second side wall. At least one ofthe first connector or the second connector may include the bracketcoupler.

The diffuser plate may include at least one paraboloid which is convexin a traveling direction of the light emitted from the light emitter.

The diffuser plate may include a flat incident surface of the lightemitted from the light emitter and a convex emitting surface of thelight emitted from the light emitter.

The reflective plate may include a bottom reflective plate and a sidereflective plate extending from the bottom reflective plate and havingan inclination.

The reflective plate may further include a fixing protrusion extendingfrom the side reflective plate. The case may further include a couplingrecess coupled to the fixing protrusion.

The side reflective plate of the reflective plate may have a firstinclination. The reflective plate may further include an auxiliaryreflective plate extending from the side reflective plate and having asecond inclination. The first inclination may be different from thesecond inclination.

The reflective plate may further include a fixing protrusion extendingfrom the auxiliary reflective plate. The case may further include acoupling recess coupled to the fixing protrusion.

The diffuser plate may include a locking part. At least one of thereflective plate or the case may include a fastener fastened to thelocking part.

The reflective plate may include the fastener. The case may furtherinclude a coupling recess into which an end of the reflective plate isinserted. The fastener of the reflective plate may be disposed closer tothe light emitter than the end of the reflective plate.

The locking part of the diffuser plate may include at least one of alocking projection or a locking hole.

BRIEF DESCRIPTION OF THE DRAWINGS

Arrangements and embodiments may be described in detail with referenceto the following drawings in which like reference numerals refer to likeelements and wherein:

FIGS. 1 a to 1 d are cross sectional views of a first single lightingmodule 10A;

FIGS. 2 a to 2 d are cross sectional views of a second single lightingmodule 10B;

FIGS. 3 a to 3 d are cross sectional views of a third single lightingmodule 10C;

FIG. 4 is a perspective view of a lighting device 1A according to afirst embodiment;

FIG. 5 is a perspective view showing a cross section of the lightingdevice 1A according to the first embodiment;

FIG. 6 is a cross sectional view of the lighting device 1A according tothe first embodiment;

FIG. 7 is an exploded perspective view of the lighting device 1Aaccording to the first embodiment;

FIG. 8 is a cross sectional view of two cases 100 of the lighting device1A according to the first embodiment;

FIG. 9 is a perspective view showing a light emitter 200 coupled to areflective plate 400;

FIGS. 10 a and 10 b are exploded perspective views of the light emitter200 and the reflective plate 400;

FIGS. 11 a and 11 b are cross sectional views of a lighting device 1Baccording to a second embodiment;

FIGS. 12 a and 12 b are cross sectional views of another example of thelighting device 1B according to the second embodiment;

FIG. 13 is a perspective view of a lighting device 1C according to athird embodiment;

FIG. 14 is a cross sectional view of the lighting device 1C according tothe third embodiment;

FIG. 15 is a cross sectional view of a lighting device 1D according to afourth embodiment;

FIG. 16 is a cross sectional view of a lighting device 1E according to afifth embodiment;

FIG. 17 is a cross sectional view of another example of a case 100 ofthe lighting device 1E according to the fifth embodiment;

FIG. 18 is a cross sectional view of further another example of the case100 of the lighting device 1E according to the fifth embodiment;

FIG. 19 is an exploded perspective view of a lighting device 1Faccording to a sixth embodiment;

FIG. 20 is a perspective view of the lighting device 1F according to thesixth embodiment;

FIG. 21 is a cross sectional view of the lighting device 1F according tothe sixth embodiment;

FIG. 22 is a cross sectional view of another example of the reflectiveplate 400;

FIG. 23 is a perspective view of a power supply controller 20;

FIG. 24 is a front view of the power supply controller 20;

FIG. 25 is a perspective view showing an embodiment 300A of a diffuserplate 300;

FIG. 26 is a perspective view showing another embodiment 300B of thediffuser plate 300;

FIG. 27 is a perspective view showing further another embodiment 300C ofthe diffuser plate 300;

FIG. 28 is a perspective view showing still another embodiment 300D ofthe diffuser plate 300;

FIG. 29 is a perspective view of an embodiment of a side cover 40;

FIG. 30 is a perspective view of another embodiment of the side cover40;

FIG. 31 is a perspective view showing an embodiment 30A of a bracket 30;

FIG. 32 is a perspective view showing another embodiment 30B of thebracket 30;

FIG. 33 is a cross sectional view of another embodiment of a lightingdevice including a single lighting module coupled thereto by using thebracket 30A;

FIG. 34 is a cross sectional view of further another embodiment of alighting device including a single lighting module coupled thereto byusing the bracket 30A;

FIG. 35 is a cross sectional view of another embodiment of a lightingdevice including a single lighting module coupled thereto by using thebracket 30B;

FIG. 36 is a cross sectional view of further another embodiment of alighting device including a single lighting module coupled thereto byusing the bracket 30B;

FIG. 37 is a perspective view of further another embodiment 30C of thebracket 30;

FIG. 38 is a perspective view shows a structure in which the bracket 30Cinterconnects the single lighting modules 10;

FIG. 39 is a cross sectional view of a lighting module including alouver 130 having another shape;

FIG. 40 is a cross sectional view of a lighting module including thelouver 130 having further another shape;

FIG. 41 is a view for describing a louver cut-off angle θ and a coverangle α of the cover angle of the lighting device according to theembodiment;

FIG. 42 is a perspective view of a support frame 50;

FIG. 42 is a cross sectional view of the support frame 50;

FIG. 44 is a cross sectional view showing how the support frame 50 iscoupled to an M-BAR of a ceiling;

FIG. 45 is a cross sectional view showing how the support frame 50 iscoupled to a T-BAR of a ceiling.

DETAILED DESCRIPTION

Hereafter, an embodiment will be described in detail with reference tothe accompanying drawings. However, it can be easily understood by thoseskilled in the art that the accompanying drawings are described only foreasily disclosing the contents of the present invention and the scope ofthe present invention is not limited to those of the accompanyingdrawings.

A criterion for “on” and “under” of each layer will be described basedon the drawings. A thickness or a size of each layer may be magnified,omitted or schematically shown for the purpose of convenience andclearness of description. The size of each element may not necessarilymean its actual size.

In description of embodiments, if there is no particular criterion foran upper surface and a lower surface of each component layer, drawingsare regarded as the criterion. Here, on the basis of the drawings, it isgenerally assumed that a surface on which a bottom plate of a case islocated is a lower surface, and a surface on which a diffuser plate islocated is an upper surface. However, in FIGS. 7, 13, 19 and 41, it isassumed that a surface on which a bottom plate of a case is located isan upper surface, and a surface on which a diffuser plate is located isa lower surface. The top and bottom of each component layer will bedescribed on the basis of the drawings. A thickness or size of eachcomponent is magnified, omitted or schematically shown for the purposeof convenience of description and clearness. The size of each componentdoes not necessarily mean its actual size. In the case where a referencenumeral is not added to a term of “a lighting device”, it means that thelighting device includes lighting devices 1A, 1B, 1C, 1D, 1E and 1Faccording to a first to a sixth embodiment.

It will be understood that when an element is referred to as being ‘on’or “under” another element, it can be directly on/under the element, andone or more intervening elements may also be present. When an element isreferred to as being ‘on’ or ‘under’, ‘under the element’ as well as ‘onthe element’ can be included based on the element.

Further, throughout the specification, when it is mentioned that aportion is “connected” to another portion, it includes not only “isdirectly connected” but also “electrically connected” with anotherelement placed therebetween. Additionally, when it is mentioned that aportion “includes” an element, it means that the portion does notexclude but further includes other elements unless there is a specialopposite mention.

Hereafter, a first single lighting module, a second single lightingmodule, a third single lighting module and lighting devices according toembodiments thereof will be described with reference to FIGS. 1 a to 41.

Single Lighting Module

Unlike a usual lighting device, a lighting device 1 to be described inthe following embodiments is formed in a particular manner. That is, thelighting device 1 is formed to include one single lighting module 10 andone power supply controller 20 or is formed to include a plurality ofthe single lighting modules 10 and at least one power supply controller20. Since the lighting device 1 having various sizes is formed of onesingle lighting module 10 or is formed through combination of aplurality of the single lighting modules 10, a lighting device 1 havinga desired size is not limited to be formed.

In the single lighting module 10, a first single lighting module 10A, asecond single lighting module 10B and a third single lighting module 10Cwill be described. There may be also a single lighting module havinganother shape.

FIGS. 1 a to 1 b are cross sectional views of a first single lightingmodule 10A. FIGS. 2 a to 2 b are cross sectional views of a secondsingle lighting module 10B. FIGS. 3 a to 3 b are cross sectional viewsof a third single lighting module 10C. Referring to FIGS. 1 a to 3 b and8, the single lighting module 10 may include a case 100, a light emitter200 disposed on the bottom plate 110 of the case 100, a reflective plate400 which is in contact with and disposed on the top surface of thelight emitter 200 and a diffuser plate 300 spaced from and disposed overthe light emitter 200.

As shown in FIGS. 1 b, 2 b and 3 b, the light emitter 200 of the singlelighting module 10 may be disposed at a contact area of a side wall 120of the case 100 and a louver 130 extending from the side wall 120 suchthat the light emitter 200 is adjacent to the diffuser plate 300.Accordingly, the light emitter 200 may be disposed closer to thediffuser plate 300 than the bottom plate 110 of the case 100. As aresult, the amount of light which is emitted directly through thediffuser plate 300 is more than that of the light which is reflected bythe reflective plate 400 and emitted through the diffuser plate 300.Therefore, the amount of the light of the lighting device may beincreased.

Since the light emitter 200 does not contact with the bottom plate 110of the case 100, a heat radiator 230 may be further included contactingwith a substrate 220 of the light emitter 200 for the purpose ofradiating the heat from the light emitter 200. Here, the heat radiator230 may include either heat radiating fins increasing the surface arearadiating heat or a heat radiation sheet 240 to be described later. Theheat radiating fins may be adhered to the heat radiation sheet 240.Accordingly, heat radiation performance can be more improved.

Since the light emitter 200 is located at a contact area of the sidewall 120 of the case 100 and the louver 130 such that the light emitter200 is adjacent to the diffuser plate 300, there may be a space betweenthe bottom plate 110 of the case 100 and the light emitter 200.Accordingly, the heat radiator 230 may be disposed between the substrate220 and the bottom plate 110.

While the lighting device to be described later according to theembodiment includes the single lighting module 10 shown FIGS. 1 a, 2 aand 3 a, the lighting device may include the single lighting module 10shown FIGS. 1 b, 2 b and 3 b.

The first single lighting module 10A is used to form a lighting deviceof a first embodiment in which the two first single lighting modules 10Aare coupled to each other in a direction perpendicular to the direction“a” in FIG. 7. Otherwise, when a lighting device of a third embodimentis formed by coupling the three single lighting modules 10 havingrespectively one light emitter 200 in a direction perpendicular to thedirection “a” in FIG. 13, the first single lighting modules 10A arearranged at both sides of the three single lighting modules 10.Otherwise, when a lighting device of another embodiment (not shown) isformed by coupling four or more single lighting modules 10 havingrespectively one light emitter 200 in a direction perpendicular to thedirection “a” in FIG. 13, the first single lighting modules 10A arearranged at both sides of the single lighting modules 10.

Referring to FIGS. 1 a, 5, 6 and 8, the case 100 of the first singlelighting module 10A includes the bottom plate 110, a side wall 120extending in a perpendicular direction to and from the both side ends ofthe bottom plate 110, a louver 130 extending from the end of the sidewall 120 and inclined at an obtuse angle with respect to the surface ofthe diffuser plate 300. Like a lighting device 1B of a second embodimentshown in FIGS. 11 a, 11 b, 12 a and 12 b, a top plate 140 may beincluded instead of the louver 130.

A first bracket coupler 151 for interconnecting the single lightingmodules 10 is formed at the end of the louver 130 on one side of thecase 100 of the first single lighting module 10A. A ceiling fixed typeframe 160 is formed at the end of the louver 130 on the other side ofthe case 100. Here, while the first bracket coupler 151 is formed at theend of the louver 130 on one side of the case 100 of the first singlelighting module 10A, the ceiling fixed type frame 160 is not necessarilyformed at the end of the louver 130 on the other side of the case 100.Accordingly, the first single lighting module 10A has the first bracketcoupler 151 formed at the end of the louver 130 on only one side of thecase 100. Here, from this point of view, the first single lightingmodule 10 is different from the second single lighting module to belater described.

The second lighting module 10B is used to form a lighting device of afourth embodiment. The lighting device of the fourth embodiment includesonly one single lighting module having one light emitter 200. Otherwise,when a lighting device of the third embodiment is formed by coupling thethree single lighting modules having respectively one light emitter 200in a direction perpendicular to the direction “a” in FIG. 13, the secondsingle lighting modules 10B may be arranged in the middle or at bothsides of the three single lighting modules 10. Otherwise, when alighting device of another embodiment (not shown) is formed by couplingfour or more single lighting modules having respectively one lightemitter 200 in a direction perpendicular to the direction “a” in FIG.13, the second single lighting modules 10B may be arranged in the middleor at both sides of the single lighting modules 10.

Referring FIGS. 2 a, 13 and 14, the case 100 of the second singlelighting module 10B includes the bottom plate 110, the side wall 120extending in a perpendicular direction to and from the both side ends ofthe bottom plate 110, the louver 130 extending from the end of the sidewall 120 and inclined at an obtuse angle with respect to the surface ofthe diffuser plate. The top plate 140 may be included instead of thelouver 130. The first bracket couplers 151 for interconnecting thesingle lighting modules 10 is formed at the ends of both louvers 130 ofthe case 100 of the second single lighting module 10B.

The third single lighting module 10C is used to form a lighting deviceof a fifth embodiment shown in FIG. 16. The lighting device of the fifthembodiment includes one single lighting module having two light emitters200. Otherwise, the third single lighting module 10C is used to form alighting device of a sixth embodiment in which the two third singlelighting modules 10C having respectively two light emitters 200 arecoupled to each other in a direction perpendicular to the direction “a”of FIG. 19. Otherwise, the third single lighting module 10C is used tofaun a lighting device of another embodiment (not shown) in which threeor more two third single lighting modules 10C having respectively twolight emitters 200 are coupled to each other in a directionperpendicular to the direction “a” of FIG. 19.

The case 100 of the third single lighting module 10C will be describedin the following description of the fifth embodiment.

As shown in FIGS. 1 c, 1 d, 2 c, 2 d, 3 c and 3 d, the case 100 and thereflective plate 400 may respectively include projections 115 and 415projecting to face each other. The diffuser plate 300 may include alocking part 350 by which the projection 115 of the case 100 or theprojection 415 of the reflective plate 400 is caught. Accordingly, thediffuser plate 300 is fixed to the case 100 or the reflective plate 400due to the weight of the diffuser plate 300. As such, the projections115 and 415 and the locking part 350 make it simpler to fasten thediffuser plate 300 to the case 100 or the reflective plate 400 than tofasten the diffuser plate 300 of FIG. 1 a.

The locking part 350 may be a locking projection or a locking hole. Thelocking hole is shown in dotted lines of FIGS. 1 c, 1 d, 2 c, 2 d, 3 cand 3 d. When the locking part 350 is the locking hole, since theprojections 115 and 415 are inserted into the locking hole, the diffuserplate 300 can be more securely fixed to the case 100 or the reflectiveplate 400.

The characteristics of the lighting device including the single lightingmodule shown in FIG. 1 a, 2 a or 3 a to be described later can becommonly applied to the lighting device including the single lightingmodules shown in FIGS. 1 c, 1 d, 2 c, 2 d, 3 c and 3 d.

First Embodiment

FIG. 4 is a perspective view of a lighting device 1A according to afirst embodiment. FIG. 5 is a perspective view showing a cross sectionof the lighting device 1A according to the first embodiment. FIG. 6 is across sectional view of the lighting device 1A according to the firstembodiment. FIG. 7 is an exploded perspective view of the lightingdevice 1A according to the first embodiment. FIG. 8 is a cross sectionalview of two cases 100 of the lighting device 1A according to the firstembodiment. FIG. 9 is a perspective view showing a light emitter 200coupled to a reflective plate 400. FIG. 10 a is an exploded perspectiveviews of the light emitter 200 and the reflective plate 400.

Referring to FIG. 4 to 8, the lighting device 1A may include two firstsingle lighting modules 10A, a power supply controller 20 located in aspace 170 between the two first single lighting modules 10A, a bracket30 for interconnecting the two first single lighting modules 10A, andadditionally a side cover 40. In FIG. 1 a, the first single lightingmodule 10A used in the first embodiment may include the case 100, thelight emitter 200 received by the case 100, and the diffuser plate 300spaced from the light emitter 200, and additionally the reflective plate400.

Referring to FIG. 4 to 8, while the two first single lighting modules10A are included in the first embodiment, the two second single lightingmodules 10B may be also used to construct the first embodiment. Thesecond single lighting module 10B has the first bracket couplers 151formed at the ends of both louvers 130. Therefore, in forming theoverall external appearance shown in the first embodiment, theappearance and function of the lighting device formed by coupling thetwo second single lighting modules 10B are little different from thoseof the lighting device formed by coupling the two first single lightingmodules 10A.

Referring to FIGS. 5 and 6, the light emitter 200 may be arranged on thebottom plate 110 of the case 100. The power supply controller 20 may bearranged in a space 170 between the two first single lighting modules10A. That is, the space is formed by the louver 130 in which the firstbracket coupler 151 are formed and by the side wall 120 connected to thelouver 130. In this case, since the power supply controller 20 isstacked under the bottom plate 110 and arranged in a horizontaldirection to the bottom plate 110 instead of in a vertical direction,the lighting device 1A has a thickness smaller than that of a usuallighting device.

The ceiling of a building in which a ceiling buried type lighting deviceis disposed has generally a concrete structure. A structure called anM-BAR or a T-BAR is provided in a direction from the ceiling to thebottom surface of the building. Tex and the like are added to the M-BARor T-BAR. Generally, in a directly downward type lighting deviceprovided on the ceiling of the building, the power supply controller 20is stacked under the bottom plate 110 and arranged in a verticaldirection, so that the thickness of the lighting device is often greaterthan 70 mm. However, since electrical wiring and an air conditioningpipe and the like are arranged between the ceiling of the concretestructure and the M-BAR or T-BAR, it is often that a space for disposinga lighting device is very small. Therefore, when a usual directlydownward type lighting device is buried and disposed on the ceiling dueto the space constraint, it is required that the M-BAR be partlytruncated or the lighting device be provided at an undesired position.

On the other hand, since the lighting device 1A according to the firstembodiment may have a thickness of about 45 mm, it is possible to freelyarrange the lighting device on the ceiling regardless of a narrow spaceand to easily and simply install the lighting device. The thickness of45 mm is provided for illustration only in order to compare with aconventional lighting device. Therefore, the size of the lighting device1A according to the first embodiment may be variously changed dependingon numerical values of the thickness of the power supply controller 20and/or the case 100 and the like.

While the lighting device 1A may have a rectangular shape extending inthe first direction “a”, the lighting device 1A may have various shapesin accordance with its installation position and its installationenvironment.

Both louvers 130 of the light emitter 200 is inclined at an obtuse anglewith respect to the surface of the diffuser plate 300 for the purpose ofallowing light emitted from the light emitter 200 to be emitted and tohave a desired light distribution angle and of alleviating glare fromthe light. If it is not possible to specify an angle based on thediffuser plate 300 due to no diffuser plate 300, the louver 130 may bespecified to be extended from the end of the side wall 120 and to beinclined more outward than the side wall 120.

The inclination of the louver 130 may be diversely changed according tothe design of the lighting device 1A. Referring to FIGS. 9 and 10 a, thelight emitter 200 may include LEDs 210, a substrate 220 on which theLEDs 210 are mounted, and a heat radiating sheet 240 arranged under thesubstrate 220. The substrate 220 may have a coupling hole 225 forcoupling the case 100 to the substrate 220. The heat radiation sheet 240of the single lighting module shown in FIGS. 1 a, 2 a and 3 a contactswith the bottom plate 110 of the case 100 as well as the substrate 220,so that heat is radiated through the heat radiation sheet 240 and thebottom plate 110. Also, the heat radiation sheet 240 of the singlelighting module shown in FIGS. 1 b, 2 b and 3 b contacts with thesubstrate 220, so that heat is radiated through the heat radiation sheet240. As a result, the heat is radiated to the space between the bottomplate 110 of the case 100 and the light emitter 200.

The lighting device may further include the reflective plate 400. Thereflective plate 400 reflects light emitted from the LED 210 to theoutside of the lighting device 1 and covers the inner surface of theside wall 120 of the case 100. The reflective plate 400 may cover notonly the inner surface of the side wall 120 but the surface of thesubstrate 220 of the light emitter 200 other than an area on which theLEDs 210 are arranged.

The power supply controller 20 may include a power supply unit (PSU)(not shown) and a driving part (not shown). The power supply unit (PSU)supplies electric power to the lighting device 1A. The driving partcontrols, starts and operates the light emitter 200.

Referring to FIG. 5, the diffuser plate 300 is disposed apart from thelight emitter 200 in the direction in which light is irradiated from theLED 210. The diffuser plate 300 allows the light emitted from the LEDs210 each of which functions as a point light source to actually functionas a surface light source such that the light emitted from the lightemitter 200 obtains a uniform luminance with respect to the surface ofthe diffuser plate 300.

The light emitter 200 is arranged on the bottom plate 110 of the case100 instead of on the entire surface of the lighting device 1A.Accordingly, when a predetermined number of the LEDs 210 are used, aninterval between the LEDs 210 arranged on the bottom plate 110 of thecase 100 is less than an interval between the LEDs 210 arranged on theentire surface of the lighting device. Moreover, the amount of thesubstrate 220 used may be also reduced.

Meanwhile, in order that the light emitted from the LED 210 functioningas a point light source can actually function as a surface light sourceby passing through the diffuser plate 300, it is necessary to form adiffuse plate surface area in which the light emitted from LED 210adjacent to the aforesaid LED 210 is superposed on the light emittedfrom the aforesaid LED 210. This means that the LED 210 should besufficiently spaced from the diffuser plate 300. However, this may alsomean that as the spaced distance is increased, the thickness of thelighting device 1A is increased. Therefore, the distance between theLEDs 210 may be reduced in order to reduce the spaced distance. Asdescribed above, since the light emitter 200 is arranged on the bottomplate 110 of the case 100 instead of on the entire surface of thelighting device 1A, the width of the substrate 220 of the light emitter200 is limited to the width of the bottom plate 110 of the case 100.Eventually, the interval between the LEDs 210 arranged on the substrate220 is naturally reduced, so that the interval between the LED 210 andthe diffuser plate 300 is also reduced. The interval between the LED 210and the diffuser plate 300 is required to form the surface light source.

Accordingly, thanks to the structural benefits as mentioned above, aslim lighting device 1 can be provided. In a state where there is nodiffuser plate 300, if light is irradiated from each of the LEDs to theirradiated area, a hot spot occurs. When the shape of a light sourceitself is directly irradiated to the irradiated area, an area onto whichlight is illuminated is more clearly distinct than an area onto whichlight is not illuminated. Here, an area onto which light is irradiatedsuch that the boundary between the surrounding dark area and the areaonto which light is illuminated is clearly formed is referred to as ahot spot. When the hot spot occurs to a general indoor lighting or anoutdoor lighting such as a street lamp and the like instead of a spotlight, the uniformity of the irradiated area may be reduced. When asurface lighting device is used as shown in the embodiment, the hot spotis reduced more than that of a general point lighting device. Therefore,there are advantages that it is possible to obtain a uniform illuminancedistribution of the irradiated area and to reduce the fatigue of theeyes.

Second Embodiment

Hereinafter, a lighting device 1B according to a second embodiment willbe described in detailed focusing on its components. In description ofthe second embodiment, the first embodiment will be applied with respectto the same parts as those of the first embodiment. The repetitivedescription thereof will be omitted. FIGS. 11 a and 11 b are crosssectional views of a lighting device 1B according to a secondembodiment. FIGS. 12 a and 12 b show another example of the lightingdevice 1B according to the second embodiment.

The biggest difference between the lighting device according to thesecond embodiment and the lighting device according to the firstembodiment is that the case 100 includes the top plate 140 instead ofthe louver 130.

Referring to FIGS. 11 a, 11 b, 12 a and 12 b, while the two first singlelighting modules 10A are included in the second embodiment, it is alsopossible to construct the lighting device according to the secondembodiment by using the two second single lighting modules 10B. Thesecond single lighting module 10B has the first bracket couplers 151formed at the ends of both top plates 140. Therefore, in forming theoverall external appearance shown in the first embodiment, theappearance and function of the lighting device formed by coupling thetwo second single lighting modules 10B are little different from thoseof the lighting device formed by coupling the two first single lightingmodules 10A.

Referring to FIGS. 12 a and 12 b, in a state where a distance betweenthe diffuser plate 300 and the light emitter 200 is maintained to beequal to that of FIGS. 11 a and 11 b, the side wall 120 extends higherthan that of FIGS. 11 a and 11 b, so that a diffuser plate couplingrecess 180 is formed in the middle of the side wall 120. In this case,since the side wall 120 is in a direction perpendicular to the bottomplate 110 and/or the diffuser plate 300 and extends higher than the sidewall of the first embodiment, the glare may be prevented moreeffectively than that of the first embodiment. However, the extent ofthe area of the bottom surface onto which light is irradiated becomesless than that of the first embodiment. Otherwise, the uniformity of theilluminance distribution of the irradiated area is reduced more thanthat of the first embodiment. Accordingly, it may be possible to installand use the lighting device 1B of the second embodiment in a conditionwhere glare prevention is required prior to both the extent of the areaonto which light is irradiated and the illuminance distribution of theirradiated area.

Here, in the single lighting module of FIGS. 11 a and 12 a, the lightemitter 200 is seated on the bottom plate 110 of the case 100. In thesingle lighting module of FIGS. 11 b and 12 b, the light emitter 200 ofthe single lighting module 10 may be disposed at a contact area of theside wall 120 of the case 100 and the top plate 140 extending from theside wall 120 such that the light emitter 200 is adjacent to thediffuser plate 300. Since the heat radiator has been described above,the description thereof will be omitted.

While the lighting device to be described later according to theembodiment includes the single lighting module 10 shown FIGS. 11 a and12 a, the lighting device may include the single lighting module 10shown FIGS. 11 b and 12 b.

Third Embodiment

Hereinafter, a lighting device 1C according to a third embodiment willbe described in detailed focusing on its components. In description ofthe third embodiment, the first embodiment will be applied with respectto the same parts as those of the first embodiment. The repetitivedescription thereof will be omitted.

FIG. 13 is a perspective view of a lighting device 1C according to athird embodiment. FIG. 14 is a cross sectional view of the lightingdevice 1C according to the third embodiment.

Referring to FIGS. 13 and 14, the lighting device 1C may include twofirst single lighting modules 10A, the one second single lighting module10B located between the two first single lighting modules 10A, the powersupply controller 20 located in one or two spaces 170 formed between thefirst single lighting module 10A and the second single lighting module10B, the bracket 130 for interconnecting the single lighting modules 10Aand 10B, and additionally the side cover 40. Here, the single lightingmodules 10A and 10B may include the case 100, the light emitter 200received by the case 100, and the diffuser plate 300 spaced from thelight emitter 200, and additionally the reflective plate 400. Since thecase 100 of the first single lighting module 10A has been alreadydescribed in the first embodiment, additional description thereof willbe omitted.

Referring to FIGS. 13 and 14, while the two first single lightingmodules 10A and the one second single lighting module 10B are includedin the third embodiment, the three second single lighting modules 10Bmay be also used to construct the third embodiment. In forming thelighting device by coupling a plurality of the single lighting modules,since the first single lighting module 10A includes only one firstbracket coupler 151, the first single lighting module 10A can be usedonly on both sides of the lighting device. On the contrary to this, thesecond single lighting module 10B includes the first bracket couplers151 at the ends of both louvers 130, so that the single lighting module10B can be used on both sides or in the middle of the lighting device.In addition, the appearance and function of the lighting device formedby coupling the three second single lighting modules 10B are littledifferent from those of the lighting device formed by coupling the twofirst single lighting modules 10A to the one second single lightingmodule 10B.

In the third embodiment, at least one power supply controller 20 isrequired to start and operate the three light emitters 200. While thedrawings show that two power supply controllers 20 control the threelight emitters 200, one power supply controller 20 is able to controlthe three light emitters 200. The position of one or more power supplycontrollers 20 has been already described above.

Though not shown in FIGS. 13 and 14, the lighting device according tothe third embodiment may include the top plate 140 instead of the louver130, like the lighting device according to the second embodiment. Sincethe embodiment in which the top plate 140 is included instead of thelouver 130 has been already described in the second embodiment, thedescription thereof will be omitted.

Fourth Embodiment

Hereinafter, a lighting device 1D according to a fourth embodiment willbe described in detailed focusing on its components. In description ofthe fourth embodiment, the first embodiment will be applied with respectto the same parts as those of the first embodiment. The repetitivedescription thereof will be omitted.

FIG. 15 is a cross sectional view of a lighting device 1D according to afourth embodiment.

Referring to FIG. 15, the lighting device 1D may include one secondsingle lighting module 10B, the power supply controller 20 located onthe outer lateral surface of one side wall 120 among two side walls 120of the case 100 of the second single lighting module 10B, andadditionally the side cover 40. Here, the case 100 of the second singlelighting module 10B includes the bottom plate 110, the side wall 120extending in a perpendicular direction to and from the both side ends ofthe bottom plate 110, the louver 130 extending from the end of the sidewall 120 and inclined at an obtuse angle with respect to the surface ofthe diffuser plate. The first bracket couplers 151 for interconnectingthe single lighting modules 10 is formed at the ends of both louvers 130of the case 100 of the second single lighting module 10B.

In the fourth embodiment, unlike the first, second and thirdembodiments, since only one single lighting module 10 is provided, thereis no space 170 formed by the two louvers 130 and the side wall 120connected to the louvers 130. Therefore, the power supply controller 20is located on the outer lateral surface of one side wall among two sidewalls 120 of the case 100 of the second single lighting module 10B.Here, unlike the first, second and third embodiments, the power supplycontroller 20 may be unstably fixed. For this reason, after holes areformed through the side wall and holes are also formed through the powersupply controller 20, the holes of the side wall 120 and the holes thepower supply controller 20 are aligned with each other. Subsequently,the case 100 can be coupled to the power supply controller 20 byallowing a screw or a pin to pass through the holes formed both in theside wall 120 and in the power supply controller 20. However, a separatebracket (not shown) for coupling the power supply controller 20 to theside wall 120 is formed without forming the hole in the side wall 120 ofthe case 100, so that the case 100 may be coupled to the power supplycontroller 20.

Though not shown in FIG. 15, the lighting device according to the fourthembodiment may include the top plate 140 instead of the louver 130, likethe lighting device according to the second embodiment. Since theembodiment in which the top plate 140 is included instead of the louver130 has been already described in the second embodiment, the descriptionthereof will be omitted.

Fifth Embodiment

Hereinafter, a lighting device 1E according to a fifth embodiment willbe described in detailed focusing on its components. In description ofthe fifth embodiment, the first embodiment will be applied with respectto the same parts as those of the first embodiment. The repetitivedescription thereof will be omitted.

FIG. 16 is a cross sectional view of a lighting device 1E according to afifth embodiment. FIG. 17 shows another example of the case 100 of thelighting device 1E according to the fifth embodiment. FIG. 18 showsfurther another example of the case 100 of the lighting device 1Eaccording to the fifth embodiment.

The biggest difference between the lighting device according to thefifth embodiment and the aforesaid lighting devices according to thefirst, the second and the third embodiments is that the fifth embodimentuses the third single lighting module 10C including two light emitters200 instead of the first and the second single lighting modules 10A and10B which include one light emitter.

Referring to FIG. 16 to 18, the width of the third single lightingmodule 10C used in the lighting device according to the fifth embodimentis approximately twice as large as widths of the first and the secondsingle lighting modules 10A and 10B used in the lighting deviceaccording to the first to the fourth embodiments. The fifth embodimentincludes only one single lighting module and a space for receiving thepower supply controller 20 without interconnecting the single lightingmodules.

Compared with FIG. 17, FIG. 18 shows that the case 100 may furtherinclude a cover part formed therein for covering the space 170 forreceiving the power supply controller 20. The power supply controller 20is surrounded by the case 100, so that the power supply controller 20cannot be seen when the case 100 is viewed from the top thereof and thebottom thereof.

Referring to FIG. 16, even though the first bracket coupler 151 forinterconnecting the single lighting modules 10 is formed at the ends ofboth louvers 130 of the case 100 of the third single lighting module10C, the first bracket coupler 151 may be formed at the end of only onelouver 130 among both the outer louvers 130.

Referring to FIGS. 17 and 18, unlike the case 100 used in FIG. 16, thecase 100 includes a closed space formed therein by the outermost louver130, the outermost side wall 120 and an additional member spaced apartfrom the outermost louver 130 and the outermost side wall 120. Withrespect to the additional member, heat generated by the operation andthe like of the lighting device is transferred to the additional member,so that the whole case is able to function as a heat radiation body. Asa result, the surface area of the heat radiation body is increased,thereby improving the heat radiating effect thereof. The case 100 may beformed through an extruding molding method in order to more enhance theheat radiating effect by using the additional member.

Referring to FIG. 16, the lighting device 1E may include one thirdsingle lighting module 10C, the power supply controller 20 located inthe space 170 formed by the two inner side walls 120 and the two louvers130 of the third single lighting module 10C, and additionally the sidecover 40. Here, the third single lighting module 10C may include thecase 100, two light emitters 200 received by the case 100, and twodiffuser plates 300 spaced from the two light emitters 200, andadditionally the reflective plate 400.

The case 100 of the third single lighting module 10C includes two bottomplates 110, four side walls 120 extending in a perpendicular directionto and from the both side ends of each of the two bottom plates 110, thelouvers 130 extending from the end of the side wall 120 and inclined atan obtuse angle with respect to the surface of the diffuser plate 300.The ends of the two inner louvers 130 are connected to each other. Ifthere is no diffuser plate 300, the louver 130 may be specified to beextended from the ends of the two outermost side walls 120 and to beinclined more outward than the side wall 120.

Though not shown in FIG. 16 to 18, the lighting device according to thefifth embodiment may include the top plate 140 instead of the louver130, like the lighting device according to the second embodiment.

Sixth Embodiment

Hereinafter, a lighting device 1F according to a sixth embodiment willbe described in detailed focusing on its components. In description ofthe sixth embodiment, the fifth embodiment will be applied with respectto the same parts as those of the fifth embodiment. The repetitivedescription thereof will be omitted.

FIG. 19 is an exploded perspective view of a lighting device 1Faccording to a sixth embodiment. FIG. 20 is a perspective view of thelighting device 1F according to a sixth embodiment. FIG. 21 is a crosssectional view of the lighting device 1F according to a sixthembodiment.

Like the lighting device 1E according to the fifth embodiment, thelighting device 1F according to the sixth embodiment uses the thirdsingle lighting module 10C including two light emitters 200. Therefore,the lighting device 1F according to the sixth embodiment may use thecases 100 of FIGS. 17 and 18.

Referring to FIG. 19 to 21, the lighting device 1F may include two thirdsingle lighting modules 10C, the power supply controller 20 located inthe space 170 formed by the two inner side walls 120 and the two louvers130 of each of the third single lighting modules 10C, and additionallythe side cover 40. Here, unlike the lighting device shown in FIG. 19 to21, the lighting device may include only one power supply controller 20instead of two power supply controllers 20. In this case, the one powersupply controller 20 controls the total of four light emitters 200. Thepower supply controller 20 may be located either in the space 170 formedby the two louvers 130 and the two inner side walls 120 of the thirdsingle lighting module 10C or in a space formed by coupling the twothird single lighting modules through the bracket 30 in FIG. 21.

The lighting device 1F according to the sixth embodiment may include thetop plate 140 instead of the louver 130, just like the lighting deviceaccording to the fifth embodiment. Since the embodiment in which the topplate 140 is included instead of the louver 130 has been alreadydescribed in the fifth embodiment, the description thereof will beomitted.

Unlike the cases 100 of the third single lighting module shown in FIGS.3 a, 3 b and 16, the first bracket coupler 151 may formed at the end ofonly one louver 130 among both the outer louvers 130. In this case, onlytwo third single lighting modules 10C can be coupled to each other.Three or more third single lighting modules 10C cannot be coupled toeach other. Therefore, there is no problem in implementing the sixthembodiment. However, it is not possible to create a lighting devicehaving a size larger than that of the sixth embodiment.

Hereinafter, the components of the lighting device 1 will be described.

<Case 100>

Since the structure of the case 100 has been already described in thefirst to the sixth embodiments, the description thereof will be omitted.

Referring to FIGS. 6 and 8, when the single lighting modules are coupledadjacently to each other, the power supply controller 20 is arranged inthe space 170 formed by the louver 130 and the side wall 120. When asecond projection 22 formed in the lower end of the power supplycontroller 20 is pushed in a sliding way into a power supply controllercoupling recess 152 formed at the boundary between the side wall 120 andthe bottom plate 110 of the case 100, the case 100 can be stronglycoupled to the power supply controller 20.

Meanwhile, the power supply controller coupling recess 152 is notnecessarily formed extending as much as the length of the case 100 inthe first direction “a” shown in FIG. 7. For example, the power supplycontroller coupling recess 152 may be extended relatively extremelyshort and be a thin plate having a shape of alphabet letter “C” or “O”.In addition, without the power supply controller coupling recess 152,after holes are formed through the side wall 120 of the case 100 andholes are also formed through the power supply controller 20, the holesof the side wall 120 and the power supply controller 20 are aligned witheach other. Subsequently, the case 100 is coupled to the power supplycontroller 20 by allowing a screw or a pin to pass through the holesformed both in the side wall 120 and in the power supply controller 20.However, if the power supply controller coupling recess 152 is formed inthe case 100, it is easier to produce the case 100 by using an extrudingmolding method and it is simple to couple the case 100 to the powersupply controller 20 without an additional screw or a pin.

The bracket coupler includes the first bracket coupler 151 and a secondbracket coupler 153. The first and the second bracket couplers 151 and153 may be formed in the case 100. The first and the second bracketcouplers 151 and 153 are connected to the bracket 30, so that the singlelighting modules are securely interconnected to each other. A side covercoupling recess 154 may be formed in the case 100. The side covercoupling recess 154 is used to couple the side cover 40 to the case 100.A method by which the side cover coupling recess 154 are coupled to theside cover 40 will be described in another part of this application.

The case 100 is formed of a metallic material or a resin material andthe like which has a good heat radiating characteristic. An aluminum(Al) oxide film or silver (Ag) oxide film is formed on the surface ofthe case 100, so that the abrasion resistance, corrosion resistance andendurance of the case 100 can be obtained and a good appearance of thelighting device 1 can be obtained. The louver 130 performs an essentialfunction of preventing the glare. Additionally, the surface of thelouver 130 is surface treated to be well reflective or includes areflective member attached thereto, so that the louver 130 is able toimprove a luminous efficiency by functioning as a reflective plate, aswell as to prevent the glare.

The case 100 may be produced by integrally assembling separatelyproduced bottom plate 110, side wall 120 and louver 130 or may beentirely integrally produced. For example, the case 100 may be formed byusing an extruding molding method. The case 100 may be simultaneouslyintegrally formed with the bottom plate 110, the side wall 120, thelouver 130, the diffuser plate coupling recess 180, the first and thesecond bracket coupler 151 and 153, the power supply controller couplingrecess 152 and the side cover coupling recess 154. The case 100 isgenerally integrally formed in the direction of length thereof. If thecase 100 is integrally formed by using the extruding molding method andthe like, the cross section formed by cutting the case 100 in adirection perpendicular to the longitudinal direction thereof has auniform shape. For example, the shape of the cross section formed bycutting the middle part of the case 100 is the same as the shape of thecross section formed by cutting a part close to the end of the case 100.When the case 100 is integrally produced, it is possible to reduce theefforts to assemble the various members and to simplify themanufacturing process.

In producing the case 100, it is not necessary that the describeddiffuser plate coupling recess 180, the first and the second bracketcoupler 151 and 153, the power supply controller coupling recess 152 andthe side cover coupling recess 154 and the like are simultaneouslyproduced. It is also possible to allow at least one member to beintegrally produced with the case 100. For example, if necessary, thecase 100 may be produced to include only the bottom plate 110, the sidewall 120, the louver 130 and the diffuser plate coupling recess 180formed therein. Otherwise, the case 100 may be produced to include onlythe bottom plate 110, the side wall 120, the louver 130 and the firstand the second bracket coupler 151 and 153 formed therein.

Referring to FIG. 8, the diffuser plate coupling recess 180 may beformed at the boundary between the inner surface of the side wall 120and the upper surface of the louver 130. Referring to FIGS. 11 a and 12a, when the top plate 140 is provided instead of the louver 130, thediffuser plate coupling recess 180 may be formed in the middle of theinner surface of the side wall 120 or at the point, which is close tothe top plate 140, of the inner surface of the side wall 120.

Referring to FIG. 8, at least one of the first and the second bracketcoupler 151 and 153, the power supply controller coupling recess 152 andthe side cover coupling recess 154 may be formed on the outer surface ofthe side wall 120 of the case 100 or on the bottom surface of the louver130. Referring to FIGS. 11 a and 12 a, when the top plate 140 isprovided instead of the louver 130, at least one of the first and thesecond bracket coupler 151 and 153, the power supply controller couplingrecess 152 and the side cover coupling recess 154 may be formed on theouter surface of the side wall 120 of the case 100 or on the bottomsurface of the top plate 140.

The case 100 is integrally formed. Therefore, since heat can beeffectively transferred to the entire case 100 and be radiated, thelighting device can have a good heat radiating characteristic. Based onan embodiment, the louver 130 may be replaced by the top plate 140. Inmore detail, when the case 100 is formed by assembling separatelyproduced members, the members do not come in complete contact with eachother but come in partial point contact with each other. As a result,heat transferred from the light emitter 200 to the bottom plate 110 isnot sufficiently transferred to the side wall 120, and the heat of theside wall 120 is not sufficiently transferred to the louver 130, either.Therefore, all members of the case 100 cannot be sufficiently used as aheat radiating body. However, when the case 100 is integrally formed byusing an extruding molding method, the entire case 100 corresponds to asingle member. Therefore, heat generated by the light emitter 200 or thepower supply controller 20 is uniformly transferred from the bottomplate 110 through the side wall 120 to the louver 130, so that anexcellent heat radiating effect is obtained.

The heat radiating effect will be additionally described. As describedin the fifth embodiment, an additional member forming the case 100 maybe formed in the lower part of the outermost louver 130. The additionalmember is intended to improve the heat radiating effect by increasingthe surface area of the case 100. For this reason, the case 100 may haveany shape capable of enhancing the heat radiating effect by enlargingthe surface area thereof. Accordingly, the additional member is able toform a closed surface with the louver 130 and the side wall 120. Theclosed surface may have heat radiating holes formed therein. Also, thelouver 130 or the side wall 120 may have an uneven structure formedthereon and function as a heat radiating fin.

FIG. 39 is a cross sectional view of a lighting module including louvers130 having different shapes from each other. FIG. 40 is a crosssectional view of a lighting module including a louver 130 havinganother different shape. Referring to FIGS. 39 and 40, the louver 130may have a cross section having various shapes such as a rectilinearshape, a parabolic shape or a circular arc shape and the like. However,how much louver cut-off angle “θ” the louver 130 has is more meaningfulthan what shape itself the louver 130 has.

The lighting device including the louver 130 formed therein has itsspecific louver cut-off angle “θ”. It is the most important objectivethat the glare is prevented by allowing the diffuser plate 300 not todirectly come into sight at the specific louver cut-off angle “θ”.Therefore, the lighting device is required to have an appropriate louvercut-off angle “θ”.

FIG. 41 is a view for describing a louver cut-off angle “θ” and a coverangle α of a cover angle. Referring to FIG. 41, unlike the louver 130 ofFIG. 41, when the louver 130 is formed to be almost aligned with theside wall 120 so as to reduce the glare, the louver cut-off angle “θ” isreduced, and the cover angle α is increased. This means that the glaredoes not occur at an angle larger than the louver cut-off angle “θ”.Therefore, the fatigue of the eyes caused by the glare can be reduced bybeing away at even a short distance from the lighting device. However, alight diffusion range is excessively reduced, so that the irradiatedarea becomes smaller.

On the contrary, unlike the louver 130 of FIG. 41, when the louver 130is formed almost parallel with the side wall 120, the louver cut-offangle “θ” is increased, and the cover angle α is reduced. This meansthat the glare does not occur at an angle larger than the louver cut-offangle “θ”. However, since the louver cut-off angle “θ” has been alreadyexcessively enlarged, the fatigue of the eyes caused by the glare mayoccur. Meanwhile, a light diffusion range is sufficiently increased, sothat the irradiated area becomes larger.

Accordingly, a lighting device giving a priority to the increase of thearea to which light is irradiated is required to enlarge the louvercut-off angle “θ”. A lighting device giving a priority to the preventionof the glare is required to reduce the louver cut-off angle “θ”.

The louver cut-off angle “θ” may have a value between 0° and 90°. Whenthe louver cut-off angle “θ” has a value within the aforementionedrange, direct light from the diffuser plate 300 cannot be seen as thelighting device is viewed from one side to the other side of thediffuser plate 300.

Since the light emitter 200 is arranged on the bottom plate 110 of thecase 100, the bottom plate 110 has a width and a length for arrangingthe light emitter 200. The diffuser plate coupling recess 180 may beformed at a position where the side wall 120 and the louver 130 are incontact with each other. The diffuser plate 300 and/or a fixingprotrusion 430 of the reflective plate 400 may be inserted and fixedinto the diffuser plate coupling recess 180. The diffuser plate couplingrecess 180 may have a shape extending in the first direction “a” shownin FIGS. 7, 13 and 19.

The diffuser plate 300 and/or a fixing protrusion 430 of the reflectiveplate 400 are pushed in a sliding way into the diffuser plate couplingrecess 180. The side cover 40 is coupled to at least one end of the case100. Then, the diffuser plate 300 and/or the reflective plate 400 aresufficiently securely fixed. As a result, during the operation of theinstalled lighting device or the transfer of the lighting device, thediffuser plate 300 and/or the reflective plate 400 are not expected tobe separated from the lighting device.

FIGS. 1 a, 1 b, 2 a, 2 b, 3 a and 3 b show that the side wall 120 of thecase 100 extends in a direction perpendicular to the bottom plate 110.Here, the side wall 120 may extend perpendicular to or substantiallyclose to perpendicular to the bottom plate 110. Also, the side wall 120may be inclined more outward with the increase of distance from thebottom plate 110 to the side wall 120. Though not shown, an unevenstructure is formed on the bottom surface of the case 100, so that thesurface area of the case 100 is increased and the heat radiatingcharacteristic of the lighting device can be improved.

<A Plurality of Light Emitters 200>

FIG. 9 is a perspective view showing a light emitter 200 coupled to areflective plate 400. FIG. 10 a is an exploded perspective views of thelight emitter 200 and the reflective plate 400.

Referring to FIGS. 9 and 10 a, the light emitter 200 may include aplurality of LEDs 210, the substrate 220 on which a plurality of theLEDs 210 are mounted, and the heat radiating sheet 240 arranged underand in contact with the substrate 220.

A plurality of the LEDs 210 may include at least one LED emitting red,green, blue, white and yellow light and the like. For example, aplurality of the LEDs 210 include a red LED, a green LED and a blue LED.Also, a plurality of the LEDs 210 may be formed through combination ofLEDs emitting various colored lights.

A plurality of the LEDs 210 may be mounted on the substrate 220. Aprinted circuit board (PCB) may be used as the substrate 220. The PCB isfabricated by printing a circuit pattern on an insulator and includes analuminum substrate, a ceramic substrate, a metal core PCB and a usualPCB and the like. The surface of the substrate 220 may be coated with orpainted with white or silver color in order to increase reflectionefficiency.

The substrate 220 includes a circuit capable of starting and operating aplurality of the LEDs 210. As shown in FIGS. 9 and 10 a, a plurality ofthe LEDs 210 may be arranged along the rows and columns on the substrate220 or arranged in various ways. The number of the LEDs may be greateror less than that of the LEDs 210 shown in the drawings. However, if thenumber of the LEDs is exceedingly small, the lighting device has adifficulty in functioning as a surface lighting device. Therefore, anappropriate number of the LEDs 210 may be arranged in consideration ofthe function of a surface lighting device.

A coupling hole 225 may be formed on the substrate 220. The substrate220 may be coupled to the case 100 by inserting a screw or a pin intothe coupling hole 225. The heat radiating sheet 240 is arrangedcontacting with the bottom surface of the substrate 220. The heatradiating sheet 240 receives heat generated from a plurality of the LEDs210 through the substrate 220 and radiates the heat or transfers theheat to the entire case 100. The heat radiating sheet 240 may be made ofa material capable of effectively radiating heat, such as a resinmaterial or a metallic material. Also, the heat radiating sheet 240 maybe made of a viscous material and easily adhered to the bottom surfaceof the substrate 220.

<Reflective Plate 400>

FIG. 22 is a cross sectional view of another example of the reflectiveplate 400. The reflective plate 400 will be described with reference toFIGS. 9, 10 a and 22.

The reflective plate 400 may be made of a resin material or a metallicmaterial which has high reflexibility. The reflective plate 400 islocated on the substrate 220 and is disposed on the side wall 120 of thecase 100. The resin material may include, for example, a PET resin, a PCresin and a PVC resin and the like. The metallic material may include,for example, Ag or an alloy including Ag, Al or an alloy including Al, astainless material and the like. The reflective plate 400 may include abottom reflective plate 410, a side reflective plate 420 extending fromthe both sides of the bottom reflective plate 410 in such a manner as tobe inclined outwardly at a predetermined angle with respect to thebottom reflective plate 410, and may further include a fixing protrusion430 extending outward from the end of the side reflective plate 420.

An LED hole 411 is formed in the bottom reflective plate 410 of thereflective plate 400. A plurality of the LEDs 210 are inserted into theLED holes 411 and shown. Therefore, the LED holes 411 are formedcorresponding to the number and position of the LEDs 210. The LED hole411 may be formed by a punching process and also may be formed byvarious methods capable of forming a hole, such as an etching processand the like.

The side reflective plate 420 may be formed in a direction perpendicularto the bottom reflective plate 410 or, as shown in FIG. 22, may beinclined outward in the direction of the extension thereof. Wheninclined, the side reflective plate 420 may effectively reflect and emitthe light generated from a plurality of the LEDs 210. That is, since thelight from the LEDs is diffused as much as an orientation angle thereof,when the side reflective plate 420 is in a direction perpendicular tothe bottom reflective plate 410, a part of the light emitted from theLEDs may be lost. On the contrary to this, when the side reflectiveplate 420 is formed to be inclined outwardly at a predetermined anglewith respect to the bottom reflective plate 410, the light generatedfrom the LEDs 210 may be effectively reflected and emitted to theoutside.

Here, since the side reflective plate 420 is formed to be inclinedoutwardly at a predetermined angle with respect to the bottom reflectiveplate 410, the area of the bottom reflective plate 410 is smaller thanthe area of the bottom plate 110 of the case 100.

Since the thickness of the fixing protrusion 430 of the reflective plate400 is less than the width of the diffuser plate coupling recess 180 ofthe case 100, the fixing protrusion 430 can be pushed in a sliding wayinto the diffuser plate coupling recess 180. Accordingly, the reflectiveplate 400 can be fixed to the case 100.

As shown in FIG. 10 b, the reflective plate 400 may further include anauxiliary side reflective plate 425 extending from the side reflectiveplate 420. Here, an angle θ1 formed by the bottom reflective plate 410and the side reflective plate 420 may be different from an angle θ2formed by the bottom reflective plate 410 and the auxiliary sidereflective plate 425. When the angles θ1 and θ2 are appropriatelydetermined, the lighting device suitable for an installation pointthereof can be provided.

When the reflective plate 400 includes the auxiliary side reflectiveplate 425, the reflective plate 400 may further include the fixingprotrusion 430 extending outward from the end of the auxiliary sidereflective plate 425. The fixing protrusion 430 can be pushed in thecoupling recess 180 of the case 100.

The side reflective plate 420 may be formed extending from the bottomreflective plate 410 to the diffuser plate coupling recess 180 of thecase 100. Meanwhile, as shown in FIG. 22, the side reflective plate 420may extend to pass through the diffuser plate coupling recess 180 of thecase 100 and even the side wall 120 of the case 100.

Referring to FIGS. 9 and 10 a, a first electrical connection hole 421may be formed in the lower part of the side reflective plate 420 of thereflective plate 400. The light emitter 200 is electrically connected tothe power supply controller 20 through the first electrical connectionhole 421, so that electric power is supplied to the light emitter 200. Asecond electrical connection hole (not shown) is formed at a location ofthe lower part of the side wall 120 of the case 100. The locationcorresponds to the location of the first electrical connection hole 421of the reflective plate 400. Consequently, the light emitter 200 can beelectrically connected to the power supply controller 20 through thefirst electrical connection hole 421 and the second electricalconnection hole (not shown).

<Power Supply Controller 20>

FIG. 23 is a perspective view of a power supply controller 20. FIG. 24is a front view of a power supply controller 20.

Referring to FIGS. 23 and 24, the power supply controller 20 includes abody 21 and a second protrusion 22 formed in the lower end of the body21. The body 21 may include a power supply unit (PSU, not shown) and adriving part (not shown) and the like. The driving part starts, operatesand controls the light emitter 200. Since a sliding way by which thesecond projection 22 of the power supply controller 20 is coupled to thepower supply controller coupling recess 152 of the case 100 has beenalready described, the description thereof will be omitted.

A third coupling hole 23 may be formed in the second projection 22.After the second projection 22 is inserted into the power supplycontroller coupling recess 152, a coupling screw or a pin and the likeis inserted into the third coupling hole 23, so that the power supplycontroller 20 can be fixed to the case 100. But for the third couplinghole 23, the second projection 22 may be coupled to power supplycontroller coupling recess 152 by using an interference fit. The powersupply controller 20 also includes a connection line 24. The connectionline 24 allows the power supply controller 20 to be electricallyconnected to the light emitter 200. Therefore, the power supplycontroller 20 is able to supply electric power and a driving signal tothe light emitter 200. The connection line 24 connects the light emitter200 with the power supply controller 20 through the first electricalconnection hole 421 and the second electrical connection hole (notshown). The power supply controller 20 may be formed of a materialhaving a good heat radiating characteristic, such as a metallic materialor a resin material.

Since various components such as the PSU and a driving part and the likeare included in the body 21 of the power supply controller 20, it ispossible to effectively protect the components from an external impact,moisture and the like. The power supply controller 20 is easily coupledto or separated from the case 100, thereby easily changing the powersupply controller 20.

<Diffuser Plate 300>

Referring to FIGS. 1 a to 3 b and 5, the diffuser plate 300 is formedover the light emitter 200. The diffuser plate 300 allows light emittedfrom the LED 210 functioning as a point light source to be emittedthrough the diffuser plate 300. The surface of the diffuser plate 300may actually function as a surface light source such that the emittedlight obtains a uniform luminance.

Both sides of the diffuser plate 300 is inserted in a sliding way intothe diffuser plate coupling recess 180 of the case 100 in the firstdirection “a” shown in FIG. 5, so that the diffuser plate 300 is coupledto the case 100. The material of the diffuser plate 300 may be, forexample, a glass material, PMMA and PC and the like.

Since the diffuser plate 300 is arranged over the light emitter 200instead of on the entire surface of the lighting device 1, the amount ofthe used diffuser plate 300 can be reduced. The width of the diffuserplate 300 is considerably less than the length thereof. Both sides ofthe diffuser plate 300 is supported in the longitudinal directionthereof by the case 100. Therefore, the diffuser plate 300 isinsignificantly bent or drooped, so that there is no problem in commonlyusing the lighting device 1.

FIG. 25 is a view showing an embodiment 300A of a diffuser plate 300.FIG. 26 is a view showing another embodiment 300B of the diffuser plate300, FIG. 27 is a view showing further another embodiment 300C of thediffuser plate 300. FIG. 28 is a perspective view showing still anotherembodiment 300D of the diffuser plate 300.

Referring to FIG. 25 to 28, the diffuser plate 300 may have variousshapes for diversely controlling the light distribution of the emittedlight of the light emitter 200. For example, in FIG. 25, the diffuserplate 300A may have a flat shape. In FIG. 26, the diffuser plate 300Bmay have a shape having two paraboloids which are convex in thetraveling direction of the light emitted from the light emitter 200. InFIG. 27, the diffuser plate 300C may have a convex paraboloid which isconvex in the traveling direction of the light emitted from the lightemitter 200, and also may have a concave paraboloid. In FIG. 28, thelight incident surface of the diffuser plate 300D is flat and the lightemitting surface of the diffuser plate OOD is convex.

While the diffuser plate 300 may have a rectangular shape extending inthe first direction “a”, this is not necessarily required. It is oftenthat the diffuser plate 300 usually has a flat shape. However, thediffuser plate 300 may have various shapes capable of controlling thelight distribution of the light emitter 200.

The locking part 350 by which the projection 115 of the case 100 or theprojection 415 of the reflective plate 400 is caught may be formed onthe diffuser plates 300A, 300B, 300C and 300D. The variously shapeddiffuser plates 300A, 300B, 300C and 300D including the locking part 350formed thereon can be more simply coupled to the case 100 or thereflective plate 400 than the diffuser plates of FIGS. 1 a, 2 a and 3 a.

<Side Cover 40>

FIG. 29 is a view of an embodiment of a side cover 40. FIG. 30 is a viewof another embodiment of the side cover 40.

Referring to FIGS. 4, 7, 13 and 19, at least one end of the case 100 mayinclude the side cover 40. The side cover 40 may be formed on both endsof the case 100. The side cover 40 is able to prevent moisture andfilth, etc., from penetrating into the case 100, to improve the rigidityof the lighting device and to fix the light emitter 200 and the powersupply controller 20 which are received by the case 100. The side cover40 may include a plurality of coupling holes 41. The case 100 may alsoinclude a plurality of side cover coupling recesses 154.

After the side cover coupling recess 154 of the case 100 and thecoupling hole 41 of the side cover 40 are aligned with each other, thecase 100 is coupled to the side cover 40 by allowing a screw or a pin topass through the side cover coupling recess 154 and the coupling hole41. The side cover 40 is able to prevent dust or filth from penetratinginto the case 100 and to more improve the rigidity of the case 100.After a plurality of the coupling holes 41 are arranged such that aplurality of the side cover coupling recesses 154 can be seen, the sidecover 40 is coupled to the case 100 by allowing a screw or a pin to passthrough a plurality of the coupling holes 41 and a plurality of the sidecover coupling recesses 154. The coupling hole 41 of the side cover 40is not necessarily formed at a location corresponding to the location ofthe side cover coupling recess 154. The coupling hole 41 of the sidecover 40 may be formed at a location corresponding to the first bracketcoupler 151, the power supply controller coupling recess 152 and thesecond bracket coupler 153, which are formed in the case 100. In thiscase, more screws or pins are inserted into the first bracket coupler151, the power supply controller coupling recess 152 and the secondbracket coupler 153, so that the side cover 40 and the case 100 arecoupled to each other.

Since the height and width of the side cover 40 may be formed to beequivalent to those of the case 100, the shape of the side cover 40 maybe varied as shown in FIGS. 29 and 30. In addition, since the materialof the side cover 40 may be the same as that of the case 100, thedetailed description thereof will be omitted.

<Bracket 30>

FIG. 31 is a perspective view showing an embodiment 30A of a bracket 30.FIG. 32 is a perspective view showing another embodiment 30B of thebracket 30. FIG. 33 is a cross sectional view of another embodiment of alighting device including a single lighting module coupled thereto byusing the bracket 30A. FIG. 34 is a cross sectional view of furtheranother embodiment of a lighting device including a single lightingmodule coupled thereto by using the bracket 30A. FIG. 35 is a crosssectional view of another embodiment of a lighting device including asingle lighting module coupled thereto by using the bracket 30B. FIG. 36is a cross sectional view of further another embodiment of a lightingdevice including a single lighting module coupled thereto by using thebracket 30B.

Referring to FIGS. 31 and 32, the brackets 30A and 30B include a fixedplate 31, a lighting module coupling member 32 which extends from oneend of the fixed plate 30 and is coupled to the first bracket coupler151 of the case 100, and a safety ring 38 extending from one end of thefixed plate 30. The lighting module coupling member 32 and/or the safetyring 38 may be formed not only at one end of the fixed plate 30, but atthe other end of the fixed plate 30.

Referring to FIGS. 6 and 11 a, it can be seen that how the case 100 iscoupled to the bracket 30 in the first embodiment and that how the case100 is coupled to the bracket 30 in the second embodiment. The fixedplate 30 is pushed in a sliding way into the second bracket coupler 153of the case 100. As the lighting module coupling member 32 has a throughhole, the lighting module coupling member 32 is coupled to the firstbracket coupler 151 of the case 100 by allowing a screw or a pin to passthrough the through hole.

Referring to FIGS. 33 and 34, the first bracket coupler 151 of the case100 has a shape different from that of FIGS. 6 and 11 a. However, amethod by which the case 100 is coupled to the bracket 30 is the same asthat of FIGS. 6 and 11. That is, the fixed plate 30 is pushed in asliding way into the second bracket coupler 153 of the case 100. As thelighting module coupling member 32 has a through hole, the lightingmodule coupling member 32 is coupled to the first bracket coupler 151 ofthe case 100 by allowing a screw or a pin to pass through the throughhole.

Referring to FIGS. 35 and 36, as compared with the bracket 30A shown inFIGS. 33 and 34, the bracket 30B also includes the fixed plate 30 andthe safety ring 38. However, the shape of the lighting module couplingmember 32 and a method by which the lighting module coupling member 32is coupled to the first bracket coupler 151 of the case 100 aredifferent from those of FIGS. 33 and 34. The lighting module couplingmember 32 does not include a through hole through which a screw or a pinpasses. Instead, the lighting module coupling member 32 has a shapecapable of hanging over and being fixed to the first bracket coupler151. The first bracket coupler 151 used in this case has a shapedifferent from that of the first bracket coupler 151 shown in FIGS. 6,11 a, 33 and 34. Unlike the bracket 30A shown in FIGS. 31, 33 and 34,the bracket 30B shown in FIGS. 32, 35 and 36 can be coupled in a slidingway to the first bracket coupler without a screw or a pin.

The first bracket coupler 151 is formed at one end of the louver 130 ofthe case 100. The second bracket coupler 153 is formed in the louver 130or in the side wall 120. Meanwhile, when the top plate 140 is providedinstead of the louver 130, like the second embodiment shown in FIGS. 11a and 12 a, the first bracket coupler 151 is formed at one end of thetop plate 140 of the case 100, and second bracket coupler 153 is formedin the side wall 120.

The safety ring 38 prevents the provided lighting device 1 from beingseparated from the provided position or being damaged by falling down tothe ground due to earthquake or other impacts, or prevents a person whois under the lighting device 1 from being hurt. A rope passing throughthe safety ring 38 is fixed within the ceiling. In this case, eventhough the lighting device 1 is separated from its provided position byimpact, the rope fixed within the ceiling holds the safety ring 38 andprevents the lighting device 1 from falling down to the bottom surface.Therefore, the bracket 30 having the safety ring 38 includes not only anoriginal function of connecting the single lighting modules, but anadditional function of obtaining safety.

It is not necessary that only one bracket 30 is coupled to the case 100in the longitudinal direction of the case 100. A plurality of thebrackets 30 may be coupled to the case 100 so as to improve the couplingrigidity between the single lighting modules or so as to obtain safety.

FIG. 37 is a view of further another embodiment 30C of the bracket 30.FIG. 38 is a view shows a structure in which the bracket 30Cinterconnects the single lighting modules 10.

Referring to FIG. 38, a plurality of the brackets 30C may be arranged onthe lighting device 1, that is, the outer lateral surface of the case100. The bracket 30C having such a shape is used to interconnect thecases 100 having no separate first bracket coupler 151, like the case100 shown in FIGS. 17 and 18 or the case 100 shown in FIG. 38. Thebracket 30C includes two planes which are in contact with each other ata right angle. The two planes include a first plane 33 coupled to theouter lateral surface of the case 100, and a second plane 35 coupled toan outer support member such as a ceiling or a wall surface, etc., or tothe outer lateral surface of the case 100. The first plane 33 includes afirst coupling hole 34. The second plane 35 includes a second couplinghole 36. The single lighting modules are interconnected by inserting acoupling screw, etc., into the first and the second coupling holes 34and 36. Also, the lighting device 1 may be coupled to an outer supportmember by inserting a coupling screw, etc., into the first and thesecond coupling holes 34 and 36. The bracket 30C may be integrallyformed with the case 100.

<Support Frame 50>

FIG. 42 is a perspective view of a support frame 50. FIG. 42 is a crosssectional view of the support frame 50. FIG. 44 is a cross sectionalview showing how the support frame 50 is coupled to an M-BAR of aceiling. FIG. 45 is a cross sectional view showing how the support frame50 is coupled to a T-BAR of a ceiling.

Referring to FIG. 42 to 45, a support frame 50 includes a frame body 51surrounding the outer lateral surface of the case 100, a case support 53extending from the inner lateral surface of the frame body 51 andsupporting the weight of the case 100, a ceiling fixed part 52 extendingfrom the outer lateral surface of the frame body 51 and being fixed tothe ceiling. As shown in FIG. 43, the frame body 51 may have an innerempty space in order to reduce its weight.

The case support 53 comes in contact with the end of the louver 130 ofthe case 100 and supports the weight of a member including the case 100and forming a lighting device. A distance between the case supports 53located at a position corresponding to the side cover 40 may be somewhatshorter than a distance between the outermost louvers 130 of thelighting device so as to prevent the members of the lighting deviceother than the support frame 50 from dropping through an opening of thesupport frame 50. If the distance between the between the case supports53 is shorter than necessary, the inclined plane of the louver 130 maybe hidden. This is not preferable. Therefore, the distance between thecase supports 53 may be formed in such a manner that the inclined planeof the louver 130 is not hidden.

The ceiling fixed part 52 fixes the lighting device to the ceiling.Moreover, if there is a space between the case 100 and the ceiling onwhich the case 100 is installed, the ceiling fixed part 52 hides thespace and allows the lighting device to have a beautiful appearance. Theceiling fixed part 52 may have a ceiling coupling recess 54.

Referring to FIGS. 43 and 44, the lighting device may be fixed to theceiling by allowing a screw to pass through the ceiling coupling recess54, TEX and an M-BAR.

Referring to FIGS. 43 and 45, due to the weight of the lighting deviceitself, the lower surface of the ceiling fixed part 52 contacts withT-BAR. Under this condition, the lighting device is fixed to theceiling. In this case, the ceiling fixed part 52 does not necessarilyinclude the ceiling coupling recess 54. However, considering that thelighting device is installed in the M-BAR as well as the T-BAR, theceiling fixed part 52 may include the ceiling coupling recess 54.

In particular, the support frame 50 can be flexibly used for variousinstallation environments. The area of a ceiling on which lightingdevices are installed are changed according to countries or a ceilingstructure. In the embodiments described above, a lighting device havingvarious sizes is created through combination of the single lightingmodules 10. However, if the lighting device fixed to the ceiling has anempty space formed between the ceiling and the lighting device, thelighting device has a bad appearance and is unstably fixed. In thiscase, if several tens of to hundreds of the standards of the singlelighting module 10 are provided to overcome the problems in order to besecurely fixed and to obtain a beautiful appearance, there occurproblems, for example, an increase of a manufacturing cost, and thelike. Therefore, as described in the aforementioned embodiments, whenthe several single lighting modules 10 having a predetermined size areused, and when the support frame 50 having various sizes is applied withrespect to the empty space between the lighting device and the ceiling,the lighting device is able to have a beautiful appearance and be stablyfixed. A member used to form the support frame 50 extends in alongitudinal direction thereof. The cross section formed by cutting themember in a direction parallel with the longitudinal direction thereofhas a uniform shape. When a rectangular shape is formed by dividing themember into four pieces and connecting the edges of the pieces, thesupport frame 50 having a necessary size can be obtained. Accordingly,it is possible to cause the production process of the support frame 50to be very simple and to allow the support frame 50 to be used forvarious ceilings. Particularly, if the member has a fixed standardexcept the length of the ceiling fixed part 52, the support frame 50 canbe almost completely used for various ceilings.

Although embodiments of the present invention were described above,these are just examples and do not limit the present invention. Further,the present invention may be changed and modified in various ways,without departing from the essential features of the present invention,by those skilled in the art. For example, the components described indetail in the embodiments of the present invention may be modified.Further, differences due to the modification and application should beconstrued as being included in the scope and spirit of the presentinvention, which is described in the accompanying claims.

What is claimed is:
 1. A lighting device comprising: a light emitterincluding a plurality of LEDs; a reflective plate disposed on the lightemitter; a diffuser plate disposed in a direction in which light emittedfrom the LED is irradiated; a case including the light emitter disposedtherein and including a bottom plate and a side wall extending from bothside ends of the bottom plate; and a connecting member extending fromthe side wall of the case and including a bracket coupler on at leastone side thereof, wherein the light emitter is disposed between thebottom plate of the case and the diffuser plate.
 2. The lighting deviceof claim 1, further comprising a heat radiator contacting with the lightemitter.
 3. The lighting device of claim 2, wherein the heat radiatorcomprises at least one of a heat radiating fin or a heat radiatingsheet.
 4. The lighting device of claim 1, wherein the light emitter isdisposed closer to the diffuser plate than the bottom plate of the case.5. The lighting device of claim 1, wherein the connection membercomprises a louver or a top plate, and wherein the bracket coupler isdisposed at an end of the louver or the top plate.
 6. The lightingdevice of claim 5, wherein the louver or the top plate is inclined moreoutward than the side wall.
 7. The lighting device of claim 1, whereinthe side wall of the case comprises a first side wall and a second sidewall opposite to the first side wall, wherein the connection membercomprises a first connector extending from the first side wall and asecond connector extending from the second side wall, and wherein atleast one of the first connector or the second connector comprises thebracket coupler.
 8. The lighting device of claim 1, wherein the diffuserplate comprises at least one paraboloid which is convex in a travelingdirection of the light emitted from the light emitter.
 9. The lightingdevice of claim 1, wherein the diffuser plate comprises a flat surfaceon which the light emitted from the light emitter is incident and aconvex surface through which the light emitted from the light emitter isemitted.
 10. The lighting device of claim 1, wherein the reflectiveplate comprises a bottom reflective plate and a side reflective plateextending from the bottom reflective plate and having an inclination.11. The lighting device of claim 10, wherein the reflective platefurther comprises a fixing protrusion extending from the side reflectiveplate, and wherein the case further comprises a coupling recess coupledto the fixing protrusion.
 12. The lighting device of claim 10, whereinthe side reflective plate of the reflective plate has a firstinclination, wherein the reflective plate further comprises an auxiliaryreflective plate extending from the side reflective plate and having asecond inclination, and wherein the first inclination is different fromthe second inclination.
 13. The lighting device of claim 12, wherein thereflective plate further comprises a fixing protrusion extending fromthe auxiliary reflective plate, and wherein the case further comprises acoupling recess coupled to the fixing protrusion.
 14. The lightingdevice of claim 10, wherein the diffuser plate comprises a locking part,and wherein at least one of the reflective plate or the case comprises afastener coupled to the locking part.
 15. The lighting device of claim1, wherein the diffuser plate comprises a locking part, and wherein atleast one of the reflective plate or the case comprises a fastenercoupled to the locking part.
 16. The lighting device of claim 15,wherein the reflective plate comprises the fastener, wherein the casefurther comprises a coupling recess into which an end of the reflectiveplate is inserted, and wherein the fastener of the reflective plate isdisposed closer to the light emitter than the end of the reflectiveplate.
 17. The lighting device of claim 15, wherein the locking part ofthe diffuser plate comprises at least one of a locking projection or alocking hole.
 18. A lighting device comprising: a light emitterincluding a plurality of LEDs; a reflective plate being disposed on thelight emitter and including a bottom reflective plate and a sidereflective plate which extends from the bottom reflective plate and hasan inclination; a diffuser plate disposed in a direction in which lightemitted from the LED is irradiated; a case including the light emitterdisposed therein and including a bottom plate and a side wall extendingfrom both side ends of the bottom plate; and a connecting memberextending from the side wall of the case and including a bracket coupleron at least one side thereof.
 19. The lighting device of claim 18,wherein the diffuser plate comprises a locking part, and wherein atleast one of the reflective plate or the case comprises a fastenercoupled to the locking part.
 20. A lighting device comprising: a lightemitter including a plurality of LEDs; a reflective plate disposed onthe light emitter; a diffuser plate being disposed in a direction inwhich light emitted from the LED is irradiated and including a lockingpart; a case including the light emitter disposed therein and includinga bottom plate and a side wall extending from both side ends of thebottom plate; and a connecting member extending from the side wall ofthe case and including a bracket coupler on at least one side thereof,wherein at least one of the reflective plate or the case includes afastener fastened to the locking part of the diffuser plate.